I have found some libraries but none of them for SqlCe 3.5. There's http://sqlcehelper.codeplex.com/ but it is not even close to done, since a significant feature like utilizing a password is not implemented. I have checked out the origin also it uses OLEdb to handle database.

The offical Microsoft Northwind example (that's shipped with SQL Compact 3.1, although not with 3.5) also does not work, I have attempted configuring it without results.

Really I do not possess a sample working code. Was anybody able to put it together combined with a passworded .sdf?
Do you know the options?
Thanks.

Several several weeks ago, I in comparison certain database implementations for the desktop application. Using SqlCE with native C++ code is awful. Basically remember right, a number of native good examples consists of "goto" type jumps, difficult to bind data and so forth. For those who have an option then use SQLite.